On board an aircraft the risk of an explosion in a fuel tank may be minimized by flooding empty tank regions with an inert gas, such as for example nitrogen. The inert gas prevents the formation of an explosive gas mixture above the fuel surface. In aircraft regions adjoining a fuel tank, however, inerting by means of an inert gas is generally not possible. For this reason, such explosion hazard regions are conventionally insulated by means of a foil. Furthermore, components that are disposed in these regions and might produce a spark or develop a high surface temperature while in operation are of an explosion-proof design and provided with special insulation. Finally, explosion hazard aircraft regions are intensively ventilated and drained, is wherein air exchange rates of 3 to 5 per minute are to be realized.
Typically, for ventilating explosion hazard aircraft regions separate systems are provided, which are so designed that in all operating situations of the aircraft they guarantee an adequate ventilation and drainage of the explosion hazard aircraft regions as well as an adequate cooling of thermally loaded components that are disposed in the explosion hazard aircraft regions. Known ventilation systems comprise for example a ram-air channel, through which during cruising of the aircraft air is directed into an aircraft region that is to be ventilated to reduce the risk of explosion. During operation of the aircraft on the ground, on the other hand, a fan ensures an adequate supply of air into the aircraft region to be ventilated. The installation of a separate ventilation system leads to additional cost, increased weight and a need for additional energy to drive the fan, which is operated electrically or by means of air drawn off from the engine.